Gutta-Percha Blowout.
Retreatment March 29th, 2007
The first xray is a duplicate which accounts for the poor quality. The case was referred to me by the patient’s new dentist. When I saw the patient, a parulis existed in the buccal furcation area. Apparently the endo was done in the 80’s and retreated by the previous dentist 1-2 years ago. That was when obturation material was pushed out the apex and the carbon fibre posts were placed and the bridge with the open distal margin was glued on.
I’m posting this case to show that extruded gutta-percha generally doesn’t cause problems.
The canals were cleared and medicated with calcium hydroxide paste for 6 weeks. The parulis disappeared. I obturated the canals.
Carbon fibre posts are a real pain to get out because I have to pretty much drill or ultrasonically destroy them to get them out; unlike metal posts which I can usually get out in one piece.
The extruded material had no impact on healing. The open margin on the distal will have an affect on healing if it isn’t addressed.
April 2nd, 2007 at 8:59 am
i never understood why people place 2 posts – that’s over-engineering a case to me. i try to avoid posts at all costs, to be honest with you. i’d say about 90% of the time you have to remove tooth structure to prep the space when you could place a nice, solid core and get a good ferrule effect on the crown.
btw, how could gutta percha have made it all the way down there? are you sure it’s not embedded in the gingiva at that sight in a manner very similar to an amalgam tattoo?
one more question – are you going to notify the referring dentist about the open margin? this is going back to our conversation about GP-specialist relationship.
April 2nd, 2007 at 11:39 am
Based on the preop film, the length and shape of extruded material, the overextended obturation in the mesial root, and the relatively wide size that I discovered the canals in this tooth to be my guess is that the following happened:
The canals, especially the mesial ones were either underprepared for their actual size or they were overprepared and apically transported like crazy. Whatever the case, the master cone was undersized for the job. Vertical condensation was done; the master cone was seared at working length minus 4-6mm as is usual for vertical condensation, and during the downpack on the remaining gutta-percha segment, it was pushed out. The canals were backfilled with gutta-percha without the operator realising what had already happened. This resulted in more extrusion of thermoplasticised material.
The posts were then put in to make my life even more difficult.
Regarding the open margin: I noted this in correspondence back to the patient’s dentist after the consultation appointment and I also told the patient. The situation wasn’t bad enough for me to refuse to do the retreatment until the margin was addressed.
One final note about posts. People forget that adhesion does not equal seal. It is no indication of how well leakage along an interface is being prevented the better something is stuck to something else. So getting a post to stay in by making them very wide, very deep (not in this case), and glueing them in with Panavia will not increase your endo prognosis and might actually increase that root’s fracture potential.
Can you believe that some dentists tell their patients they need to put a post in their tooth to strengthen the root? It makes sense to patients but is so wrong as you know.
I tell patients that what posts do in roots is the exact opposite to what rebar does in concrete because the dynamics of the materials are different. Never fails to surprise them.
April 4th, 2007 at 5:28 am
“…extruded gutta-percha generally doesn’t cause problems…”
I didn’t know that! Is GP 100% biocompatible then? Or is there an underlying foreign body reaction (note that underlying does not necessarily mean problematic)?
April 8th, 2007 at 6:30 am
You probably know more about this stuff than I remember. I’d have to look some articles up to get you details.
I tell patients that the body treats extruded GP like it does breast implants. GP is a foreign object that becomes encapsulated with fibrous connective tissue to isolate and wall it off. Breast implants become encapsulated with scar tissue in the same fashion.
In some patients the scarring becomes quite significant and a radiolucent “lesion” develops around the material. In others, but very uncommonly, the foreign body reaction persists and the lesion grows over time. I generally assume some sort of bacterial impregnation of the GP though when I see that.
There have been case reports of extruded GP getting resorbed over time via macrophage activity, but I don’t see that too often either. This situation is likely related to the progressive foreign body reaction I’ve noted in the paragraph above.
So to answer your question: I wouldn’t say that GP is 100% biocompatible (unlike titanium alloy osseous implants) because there is a somewhat negative (albeit benign) tissue response.
It’s still prudent to try to keep obturation material in canals. Especially since extruded GP usually has sealer attached to it, and the vast majority of sealers used are inflammatory during their setting phase.